On 15.10.2024 08:11, Nuno Sá wrote: > On Mon, 2024-10-14 at 16:16 -0500, David Lechner wrote: > > On 10/14/24 5:08 AM, Angelo Dureghello wrote: > > > From: Angelo Dureghello <adureghello@xxxxxxxxxxxx> > > > > > > Change to obtain the fdt use case as reported in the > > > adi,ad3552r.yaml file in this patchset. > > > > > > The DAC device is defined as a child node of the backend. > > > Registering the child fdt node as a platform devices. > > > > > > Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx> > > > --- > > > drivers/iio/dac/adi-axi-dac.c | 53 +++++++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 53 insertions(+) > > > > > > diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c > > > index b887c6343f96..f85e3138d428 100644 > > > --- a/drivers/iio/dac/adi-axi-dac.c > > > +++ b/drivers/iio/dac/adi-axi-dac.c > > > @@ -29,6 +29,8 @@ > > > #include <linux/iio/buffer.h> > > > #include <linux/iio/iio.h> > > > > > > +#include "ad3552r-hs.h" > > > + > > > /* > > > * Register definitions: > > > * https://wiki.analog.com/resources/fpga/docs/axi_dac_ip#register_map > > > @@ -738,6 +740,39 @@ static int axi_dac_bus_reg_read(struct iio_backend *back, > > > u32 reg, u32 *val, > > > return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val); > > > } > > > > > > +static void axi_dac_child_remove(void *data) > > > +{ > > > + struct platform_device *pdev = data; > > > + > > > + platform_device_unregister(pdev); > > Just do platform_device_unregister(data)... Or call the argument pdev for better > readability... > > > > +} > > > + > > > +static int axi_dac_create_platform_device(struct axi_dac_state *st, > > > + struct fwnode_handle *child) > > > +{ > > > + struct ad3552r_hs_platform_data pdata = { > > > + .bus_reg_read = axi_dac_bus_reg_read, > > > + .bus_reg_write = axi_dac_bus_reg_write, > > > + }; > > > + struct platform_device_info pi = { > > > + .parent = st->dev, > > > + .name = fwnode_get_name(child), > > > + .id = PLATFORM_DEVID_AUTO, > > > + .fwnode = child, > > > + .data = &pdata, > > > + .size_data = sizeof(pdata), > > > + }; > > > + struct platform_device *pdev; > > > + > > > + pdev = platform_device_register_full(&pi); > > > + if (IS_ERR(pdev)) > > > + return PTR_ERR(pdev); > > > + > > > + device_set_node(&pdev->dev, child); > > > > Not sure why Nuno suggested adding device_set_node(). It is > > redundant since platform_device_register_full() already does > > the same thing. > > > > Indeed... I realized that yesterday when (actually) looking at > platform_device_register_full(). You just beat me in replying to the email. Sorry for > the noise... > > > (And setting it after platform_device_register_full() would > > be too late anyway since drivers may have already probed.) > > > > + > > > + return devm_add_action_or_reset(st->dev, axi_dac_child_remove, pdev); > > > +} > > > + > > > static const struct iio_backend_ops axi_dac_generic_ops = { > > > .enable = axi_dac_enable, > > > .disable = axi_dac_disable, > > > @@ -874,6 +909,24 @@ static int axi_dac_probe(struct platform_device *pdev) > > > return dev_err_probe(&pdev->dev, ret, > > > "failed to register iio backend\n"); > > > > > > + device_for_each_child_node_scoped(&pdev->dev, child) { > > > + int val; > > > + > > I'm starting to come around again if some sort of flag (bus_controller or an explicit > has_child) wouldn't make sense (since you may need to re-spin another version). So we > could error out in case someone comes up with child nodes on a device that does not > support them. > For this, i added a check on io-backend here, that has been asked to be removed. Without adding other flags, i may use has_dac_clk, could it be ok ? > Anyways, I'll leave this up to you and maybe others can also argue about this... > > > > + /* Processing only reg 0 node */ > > > + ret = fwnode_property_read_u32(child, "reg", &val); > > > + if (ret) > > > + return dev_err_probe(&pdev->dev, ret, > > > + "child node missing."); > > > > Shouldn't the error message say that there is a problem with the reg > > property? We already have a handle to the child node, so the child node > > isn't missing. > > Makes sense... like "reg property missing" - something on those lines. > > - Nuno Sá > > >
